Hydraulic transmission



Aug.,. 17, 1943.

E. w. BAGGOTT HYDRAULIC TRANSMISSION Filed Feb. 26; 1942 2 Sheets-Sheet1 INVENTOR ATTORNEY" Aug. 17, 1943 E. w. BAGGOTT 2,327,238

HYDRAULIC TRANSMISSION Filed Feb. 26, 1942 2 Sheets-Sheet 2 ATTORNEYS,

Patented Aug. 17, 1943 HYDRAULIC TRANSMISSION Edmund W. Baggott,Brooklyn, N. Y., asslgnor of one-third to Charles Scotson and one-thirdto Harold B. Kaempi'. both of New York, N. Y.

Application February 26, 1942, Serial No. 432.425

12 Claims.

This invention relates to an improved hydraulic transmission fortransmitting power from a driving member to a driven member, and theprimary object of the invention is the provision of a simplifiedconstruction, as compared with the hydraulic transmissions of the priorart, and to provide for an infinite number of speed ratios between thedriving member and the driven member.

In the accompanying drawings I have illustrated one embodiment of theinvention:

Fig. 1 is a side elevational sectional view of one form that myinvention may take;

Fig. 2' is a section on the line 2-2 of Fig. i;

Fig. 3 is a section on the line 3-3 of Fig. i;

Fig. 4 is a section on the line 6& of Fig. 1;

Fig. 5 is a section on the line 5-5 of Fig. 1;

Fig. 6 is a section on the line li6 of Fig. 3;

Fig. 7 is a fragmentary view taken on the line 'i-i of Fig. 6; and

Figs. 8 and 9 are diagrammatic explanatory views.

Referring now to the drawings in detail: In the form illustrated myinvention comprises an outer casing 2 which is always filled with oil orother liquid. d designates the driving member. In this instance thismember is a shaft extending through one end of the casing axially of thecasing. Extending through the other end of the casing 2 is the drivenmember or shaft As will be obvious to those skilled in this art, theprimary purpose of my apparatus is to provide variable powertransmission between the driving member ii and driven member 6, theformer being connected, as will be understood, to any suitable primemover.

More specifically my invention provides a hydraulic drive ortransmission of extremely simple construction and embodying but fewparts whereby driven member 6 can be driven at an infinite number ofspeeds with varying torque.

Keyed to the driving shaft l, as shown at i, is a small gear or pinion Bmeshing with three gears m, 12 and i4 disposed about the periphery ofthe pinion, these-gears Hi, I2 and M being supported in spaced discs l6and i8 concentric with the pinion 8 and driving shaft 4. Studs 26constituting the bearings for the gears Ill, 12 and I4 each carry apinion 22, which mesh with a gear 24 bolted to the wall 26 of a rotarycasing 28 mounted within the main casing 2. The casing 28 constitutespart of what I shall term the second power transmitting unit or pump ofmy transmission. l

The disc I6, above referred to, is connected by pins or other connection30 to a disc 32 which also surrounds and is concentric with the drivingshaft 6.

The disc 32 is provided with a hub 34 extending into the non-rotatablecasing 36 of the first unit of the transmission. This casing 36 ismounted concentric with the driving shaft 4 but is held against rotationthrough the lugs 38 on the bottom of the casing and on the interior ofthe nonrotatable main casing or housing 2.

Within the first power transmitting unit or pump casing 36 is acupshaped rotor 40, the hub 34 of the disc 32 extending into this rotoralso.

Extending radially of the rotor 40 is an impeller it, this impellerextending through the rim of the rotor to and across the space betweenthis rim and the peripheral wall of the casing 36.

The side wall or bottom 39 of the cup-shaped rotor M3 is cut out toaccommodate a control disc or shifting disc M which surrounds thedriving shaft It. This disc is so constructed that it can be movedradially with respect to said driving shaft thereby to vary the settingof the rotor it within the casing 38. For example, as shown in Fig. 1,the rotor it is in its extreme eccentric position with respect to thecasing 36 as I have illustrated diagrammatically in Fig. 8 and byadjusting the control or shift disc M the rotor til can be shiftedbodily until it is concentric with the casing 35, as illustrateddiagrammatically in Fig. 9. The purpose of 'thus shifting the rotor withrespect to its enclosing casing will be brought out in more detailhereinafter. The drive for the rotor dibit will be understood, isthrough the impeller M which, as above mentioned, is fast on hub it ofthe disc 32.

In order that the control disc M may be shifted or bodily moved as abovepointed out the face of the front wall of the fixed casing 36 isprovided with a plate it, and between this plate 46 and the wall of thecasing 36 and surrounding the hub of the control member 44 is a leverplate 48, which shifts with the control disc 44.

Mounted for free rotation on the exterior of the plate 46 and concentricwith the driving shaft 4 is a bevel gear 50 in constant mesh with asmall bevel gear 52 mounted in a bracket 54 secured to the front wall ofcasing 36. A lever 56 is connected at one end to this gear 52 so thatwhen the lever is rocked. rotary motion will be imparted to 52 to rotatethe gear 50.

Connected to the gear 50 or integral therewith is an arm 58 which isforked at its free end, this fork engaging a pin 60 carried in the endof the lever 48, this lever being pivoted at 64. The lever plate 48 isconnected to the control member it.

As a result of the construction just described, it will be apparent thatwhen the lever 68 is rocked rotary motion will be imparted to the gear50 to pivot the lever plate 48 thereby to shift the control disc 44bodily and correspondingly adjust or vary or shift the rotor 40 withinthe casing 38 of the first unit.

The control disc 44 is adapted to be shifted manually and automatically.With respect to manual shifting: 86 designates a long rod extending theentire length of the fixed casing 2. Mounted on this rod is an arm 68connected by a link I to the outer end of the lever 56. The rod 88 isprovided with a fixed collar I2 and between this collar and the arm 58is a spring it. This spring permits movement of 88 toward id butmovement of St in the opposite direction is limited by a collar it whichis fast to the rod 8%.

The outer end of the arm 68 is provided with a pin I8 receiving theforked end of a link 89 which is pivoted to lever 52, the latter beingpivoted at to. The outer end 86 of the lever 82 is at the exterior ofthe casing t.

With the parts in the position shown in Fig. 1, it will be quiteapparent that if 86 be moved toward the dotted line position shown inFig. 3. rotation will be imparted to the gear St in the proper directionto move the rotor do within the casing 36 until Bil has moved from theposition shown in Fig. 8 to that shown in Fig. 9; in other words, froman eccentric position to concentric position with respect to casing 38.

Referring now to the second unit: I have already made reference tocasing or housing 28 and pointed out that the same is rotary. Withinthis casing I provide the second unit which is practically a duplicateof the first unit, but for purposes of clarity it will be necessary todescribe this second unit in detail.

Within the rotary casing 28 and concentric with the drive shaft d is thecasing 88 of the second unit, and within this casing is a rotor 9b. Thiscasing and rotor correspond to casing 36 and rotor 40 of the first unit.In this second unit, however, the casing 88 is fixed to the casing 28 asshown at 52 so as to be rotatable therewith. Casing 36 of the firstunit, it will be remembered, is stationary. t

An impeller 94 is provided for the second unit. This impeller is aduplicate of the impeller d2 of the first unit. The impeller 94 is keyedto the shaft 4 at 96. Rotor 90 is adapted to be shifted within itscasing 88 through the medium of a shift or control disc 98 which issimilar to the control disc 44 of the first unit. Shifting of 98 isaccomplished through gears I00 and I02, the

I gears I02 being rotated through the medium of arms IM. End wall I06 ofthe casing 28 is provided with a hub I08 surrounding the adjacent endsof the driving shaft 4 and driven shaft 8, this hub being keyed orpinned to the latter as shown at I09. Mounted on the driving shaft i,within the casing 28, and adjacent the wall m6 thereof is a spider IIii, connected by suitable connections II2 to a collar M5 on the hubI08, this collar being slidable on the hub.

Connected to the collar H4 is a lever M6, the inner end of which ispivoted to a link ilii pivoted to the bottom wall of the casing 2, asshown at I20. The outer end of the lever l I5 is connected to the rod 66by link I22 and arm I24, the latter being pinned to the rod.

It will be obvious that by moving the rod 66 to the left, as viewed inFig. 1, the collar Ii 4 will ass-nose be moved al the hub H08 impartingmotion in the same direction to the spider m, thereby to rock the leversI04 and impart rotation to gears I02, to rotate the gear I00 which isconnected 6 to control member 98 through levers Ill thereby to shift therotor 90 of the second unit radially with respect to its casing 00 fromthe concentric position shown in Fig. 8 toward the eccentric positionshown in Fig. 9.

The end of the driven shaft 8 beyond the end of the casing 2 is providedwith a ball governor I28. 'Lever I28 of this governor is pivoted at Iii:to a link I32 pivoted on the adjacent end wall of the casing 2. At itsouter end the lever is connected by a link 5363 to the outer end 0 therod 66. The effect of all this is that when the balls of the governori255 move outwardly due to rotation of the driven shaft the rod 63 wildbe gradually shifted to the left, as viewed in Fig. l, shifting therotors 40 and of the first and sec- 0nd units in their respectivecasings t6 and 8d.

The operation of my improved apparatus is as follows: The parts in Fig.'3. shown in low speed position, and as will be seen from diagram ofFig. 8, under these conditions the rotor 40 of the first unit is in itsextreme eccen" trio position with respect to its casing while the rotor9d of the second unit is concentric with its casing 88. Under thesecondi ons re tation of the driving shaft *3 will drive the pinion, 8 butinasmuch as the rotor id is in its e .reme eccentric position and hencelocked against rotation, because the casing 3b is locked to the fixedhousing 2 at 3%, the pinion 9 will rotate each of the gears it, I2 andIt on its own axis, which will drive the pinions 22, in turn driving thelarge gear 2 3. This gear 24 is fastened directly to the face of therotary casing 28 so that the latter is rotated, and inasmuch as its hubW8 is keyed to the driven shaft 6, the shaft 6 will be driven. At thesame time, of course, the casing 88 of the second unit is rotatedInasmuch as it is keyed to 28. Rotor 90 of the second unit is alsorotated direct from the driving shaft 4,

is no driving effect through 90 on the driven shaft.

As the shaft 6 speeds up the balls of governor I26 will move outwardlyto move the rod 86 toward the left, as viewed in Fig. 1. This movementof the rod 66 will effect rocking of the levers I I6 and 56 and throughthe connections above described will effect rotation of the gears I00and gradually to shift the control discs 98 and 44 into position so thatthe rotor 40 of the first unit will be moved gradually from the fulleccentric position shown in Fig. 8 to the concent ic position shown inFig. 9 while the rotor of the second unit will be shifted in theopposite sense, that is, from the concentric position of Fig. 8 to thefull eccentric position of Fig. 9. As soon as the rotor 40 of the firstunit moves from its extreme eccentric position with respect to its fixedcasing, the rotor is free to turn because the oil is no longer trappedbetween the rotor 40 and casing 36 and impeller 42, and inasmuch as theimpeller 42 is connected to the housing of gears I0, I2 and It thelatter are now free to move in a planetary fashion about the pinion 8,instead of these gears merely rotating on their individual axes as wasthe case when rotor 40 was held against rotation. The rotor 90 of thesecond unit is moving at this time toward its extreme eccentric positionwith 5 respect to its casing 88. Consequently there i I but inasmuch asit is set concentric with 88 there a gradual throttlin of the movementof the oil in the second unit, because th rotor 90 is gradually movingtoward the outer casing 88 and the oil is trapped between the roto andcasing and impeller 94, thereby increasing the drag on the casing 88 andhence on the casing 28, and a gradual increase in the speed of thedriven shaft 6, until finally the rotor 98 is no longer able to rotatewith respect to casing 88, and B8 is in effect locked to the shaft 4 byth pin 86. Inasmuch as 88 is locked to the casing 28 the latter ineffect is locked to 4 and we have casing'28 traveling at the same linearspeed as the drive shaft 4 and inasmuch as 28 and the driven shaft t arekeyed together shaft 6 is now rotating at the same speed as 4.

It is to be noted under these conditions, that is, extreme eccentricposition of rotor 90 01 the second unit with respect to 88, the rotor4th of the first unit is concentric with its casing 36 so that there isno opposition to free rotation of the rotor 40 within its casing 38.

It will be appreciated that between the low speed position illustratedin Fig. 8 and the high speed position illustrated in Fig. 9 an infinitenumber of speed gradations are obtained between the speeds of thedriving shaft 4 and driven shaft 6.

When it'is desired to place the parts in neutral I position, that is, sothat the driving shaft 4 may be rotated without any motion at allbeingimparted to the driven shaft 6, it is merely neces-- sary to slowthe shaft i to the point where the parts are in the low speed positionof Figs. 1 and 8, then to move the lever 86 toward the dotted lineposition of Fig. 1. This moves the rotor 4(1) of the first unitconcentric with its casing 36, and both rotors 40 and Eli will now beconcentric with their respective casing 36 and 88.

Under these conditions the ears 58, i2 and iii would simply move in aplanetary fashion about the periphery of the pinion 8 and at the sametime the pinions 22 would simply move in a planetary fashion about theperiphery of the large gear 24, and although 24 i rigidly secured to thewall 26 of the casing 28 the casing 28 would not be rotated and hencethere would be no driving effect on the driven shaft B from this casing.Furthermore, although the drive shaft t is keyed directv to the rotor 90of the second unit, and although the casing 88 of this unit isnon-rotatable with respect to the casing 28,

there is no driving effect through this mechanism on casing 28 and henceon the driven shaft 6 because of the fact that the rotor 98 is setconcentric with respect to 88. Under these conditions, therefore, theshaft 4 is rotating while the driven shaft 6 is stationary.

With reference more specifically to Figs. 3, 6 and 7: Eachof theimpellers 42 and 94 is bored longitudinally, as shown at I36. At itsinner end, that is, the end adjacent the shaft 4, this bore connectswith a bore I38 extending parallel to the shaft 4 and communicating withthe interior of the casing 2. At the outer end each impeller is providedwith a spring-loaded check valve Hill at the end of bore I36. By reasonof this construction I am assured that the space between the rotors 42and 94 and their respective casings will always be filled with oil, thevalve I40 lifting to permit oil to fiow from the casing 2 through theconduits I38 and I36 to the spaces between the rotors and their casing,upon a drop in pressure in these spaces back of the impellers.

It is to be understood that the entire apparatus is kept filled with oilor other suitable fluid.

It will be understood that various changes may be made in the details ofconstruction and arrangement of parts herein shown and described withoutdeparting from the spirit and scope of this invention.

What I claim is:

1. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of two units eachcomprising a rotor,-an enclosing casing and an impeller extending intothe space between the rotor and casing, a liquid in the said space ineach unit, a gear train connecting the driving member to one of saidrotors, the other rotor directly connected to said driving member, meansfor connecting the casing of the last mentioned rotor to the member tobe driven, and means for varying the relative positions of each rotorand its casing to vary the speed of the driven member relatively to thedriving member.

2. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of a first and secondunit each of which comprises a rotor surrounding the driving member, asurrounding casing and an impeller extending into the space between therotor and casing, liquid in said space, an additional casing enclosingsaid second unit and connected to the casing of the second unit and tothe member to be driven, a gear train connecting the driving member toone of said rotors, the other rotor being directly connected to saiddriving member, means for connecting the casing of the last mentionedrotor to the member to be driven, and means for varying the relativepositioning of the rotor and casing of each unit to vary the speed ofthe driven member relatively to the driving member.

3. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of two units eachcomprising a rotor, an enclosing casing and an impeller extending intothe space between the rotor and casing, a liquid filling the space ineach unit between the rotor and easing unoccupied by the impeller, agear train connecting.

of the last mentioned rotor to the member to be driven, and means forshifting each of said rotors relatively to its impeller to vary theposition of each of said rotors relatively to its casing to vary thespeed of the driven member relatively to the drivin member.

4. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of a first and secondunit each comprising 'a rotor, an enclosing casin and an impeller in thespace between the rotor and easing, a liquid filling the space in eachunit between the rotor and casing unoccupied by the impeller, anadditional casing en'- closing said second unit and directly connectedto the casing of the second unit and to the member to be driven, aplanetary gear train connected to the driving member, to said additionalcasing and to the rotor of the first unit, and means for shifting therotors of each unit rela tively to its impeller tovary the positioningof each rotor in its casing to eifect a variation in speed between thedriving member and the member to be driven.

5. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of a first unit and asecond unit, each comprising a rotor, an enclosing casing and animpeller in the space between the rotor and casing 01' each unit, liquidin ,he said space, a gear train connecting the driving member to one ofsaid rotors, the other rotor being directly connected to said drivingmember, means for connecting the casing of the last mentioned rotor tothe member to be driven, and means within each casing operable from theexterior thereof and engaging said rotors for moving the same bodilyrelatively to their respective casings and impellers with the rotor inoperation so as to set one rotor eccentric to its casing while the othermoves to concentric position, thereby to vary the speed or the member tobe driven without varying the speed of the driving member.

6. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of a first unit, asecond unit and an intermediate gear train, each unit comprising arotor, an enclosing casing and an impeller in the space between therotor and casing, liquid in the space between each rotor and casingunoccupied by the impeller, an additional casing for the second unit towhich the casing immediately surrounding the rotor is fixed, saidadditional casing being directly connected to the member to be driven,gearing connecting the rotor of the first unit and the said additionalcasing of the second unit to the driving member, and means for adjustingthe rotors of the said two units in their respective casings relativelyto their impellers so that when the eccentricity of one unit is beingreduced that of the other unit is being increased thereby to vary thespeed of the member to be driven relatively to the driving member.

7. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of two units eachcomprising a rotor, an enclosing casing and an impeller extending intothe Space between the rotor and casing, liquid in said space, a geartrain connecting the driving member to one of said rotors, the otherrotor being directly connected to said driving member, means forconnecting the casing of the last mentioned rotor to the member to bedriven, and means actuated by the member to be driven to shift bothrotors simultaneously radially of their respective casings and impellersautomatically to vary the speed of the driven member relatively to thator the driving member.

8. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of two units eachcomprising a rotor, an enclosing casing and an impeller extending intothe space between the rotor and easing, liquid in said space, a geartrain connecting the driving member to one 01 said rotors, the otherrotor being directly connected to said driving member, means forconnecting the casing of the last mentioned rotor to the member to bedriven, and a. governor driven off the member to be driven for shiftingboth rotors simultaneously but in opposite directions relatively totheir respective cas ss automatically to vary the speed of the drivenmember relatively to that or the driving member.

9. In a hydraulic transmission for transmitting power xz'om a drivingmember to a member to be driven, the combination of a first unit, asecond unit and an intermediate gear train, each unit comprising arotor, an'enclosing casing and an impeller in the space between therotor and easing, a liquid in said space, an additional casing for thesecond unit fixed to the casing immediately surrounding the rotor of thesecond unit and directly connected to the member to be driven, gearingconnecting the rotor of the first unit and the said additional casing tothe driving member, and means operated by the member to be driven i'orshifting said rotors relatively 01' their impellers and radially ortheir respective casings toward and from the axes of their casingsthereby to eflect variation in the relative speeds of the driving anddriven members.

10. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination or a first unitcomprising a rotor, a fixed casing and an impeller extending through therotor into the space between the rotor and casing to be driven by therotor, a second unit comprising a rotor, a rotatable casing and animpeller extending through the rotor into the space between the rotorand casing to be driven by the rotor, gearing driven off the drivingmember and connected to the rotor of the first unit and to the casing ofthe second unit, the rotor of the second unit being directly connectedto the driving member, and the casing of the second unit being connectedto the member to be driven.

11. In a hydraulic transmissionjor transmitting power from a drivingmember to a member to be driven, the combination or a first unit and asecond unit each comprising a rotor, a casing therefor and an impellerextending through the rotor periphery into the space between the rotorand casing to be driven by the rotor, the casing of the first unit beingnon-rotatable, a pinion carried by the driving member, planetary gearingdriven thereby and connected to the rotor of the first unit, and to thecasing of the second unit, the latter being directly connected to themember to be driven, while the rotor of the second unit is connected tothe driving member.

12. In a hydraulic transmission for transmitting power from a drivingmember to a member to be driven, the combination of a first unitcomprising a fixed casing, a rotor within the casing and an impellerextending radially oi the rotor into the space between the rotor andcasing to be driven by the rotor, a geared connection between said rotorand the driving member, a second unit comprising a rotor, a casing, animpeller between the rotor and easing, a rotary casing surrounding thesecond unit and connected to the said gearing and fixed to the firstmentioned casing of the second unit, the said rotary casing beingdirectly connected to the member to be driven and the rotor and impellerof the second unit being directly connected to the driving member.

EDMUND W. BAGGO'I'I'.

